Structure of Pig Skin Dermatan Sulfate

The presence of sulfated uronic acid residues in dermatan sulfate has been known for some time. In view of the copolymeric nature of pig skin dermatan sulfate, it was of interest to see whether the extra sulfate groups were attached to iduronic acid or glucuronic acid residues. Hyaluronidase‐degraded dermatan sulfate was fractionated on Dowex‐1 to yield fractions of varying sulfate content. It was observed that the degree of sulfation was invesely proportional to the glucuronic acid content. Oversulfated dermatan sulfate was subsequently treated with chondroitinase‐AC to yield a completely glucuronic acid‐free polymeric product still bearing all the extra sulfate groups. More direct evidence for the presence of sulfated induronic acid moieties was obtained by Smith degradation of oversulfated, chondroitinse‐AC treated dermatan sulfate. A fast‐moving component isolated by preparative electrophoresis had the molar ratio sulfate; hexosamine 1.8:1 and contained exclusively L‐iduronic acid.